Air conditioning systems are conventionally known that include a radiant panel and an indoor heat exchanger and provide room heating with radiant heat and warm air. For example, an air conditioning system disclosed in Patent Document 1 includes a refrigerant circuit in which a compressor, an outdoor heat exchanger, an expansion valve, an indoor heat exchanger and a radiant panel are connected in this order. The refrigerant circuit is configured to operate in a refrigeration cycle by reversibly circulating refrigerant therethrough.
According to this air conditioning system, in a heating operation (heating cycle), refrigerant discharged from the compressor flows through the radiant panel and the indoor heat exchanger in this order to condense, whereby warm air from the indoor heat exchanger and radiant heat from the radiant panel are supplied to the room. On the other hand, in a cooling operation (cooling cycle), refrigerant having condensed in the outdoor heat exchanger evaporates in the indoor heat exchanger, whereby cold air from the indoor heat exchanger is supplied to the room. The refrigerant having evaporated in the indoor heat exchanger bypasses the radiant panel and then returns to the compressor.    Patent Document 1: Published Japanese Utility Model Application No. H07-18935